Total Dissolved Solids

Ponds, streams, and rivers all contain dissolved materials. Rocks, minerals, and substances such as salt from streets (found in the winter time), and fertilizers from lawns can all be dissolved then found in our water. Wastewater treatment plants can also add phosphorous, nitrogen, and organic material that can increase the amount of Total Dissolved Solids (TDS). High TDS levels can make water taste like minerals and make it unpleasant to drink.

Rainwater – TDS levels are less than 10ppm.

Rivers – TDS levels typically between 100ppm and 2,000ppm.

Treatment plants - try to be less than 500ppm

Using a TDS meter

1. Press button on top to turn meter on. Release the button to use meter (should read "0" when not in water).

2. Place the meter in the water so water level is between the "min" and "max" lines. Hold the meter in the water for 30 seconds. Record the amount of TDS in parts per million (ppm).

What Do the Results Mean?

“Aquatic life depends upon a constant TDS level for a variety of reasons. For example, dissolved calcium affects how easily water can flow into and out of organism’s cells. High TDS levels can cause water balance problems for organisms. Low TDS levels may limit growth of aquatic life. Phytoplankton and floating aquatic plants, for example, absolutely require the nitrates and phosphates dissolved in the water because they have no roots to take up those nutrients.”